Presently swimming pool cleaning devices typically include a roller brush assembly, wheels and/or a track and/or a chain placed at the bottom of the body. Such a roller brush assembly, wheels and/or track and/or chain are driven by an internal motor, or jet propelled by water pump placed inside or outside the swimming pool cleaning device. The swimming pool cleaning device can therefore move around at the swimming pool floor to vacuum and to clean the pool.
U.S. Pat. No. 5,001,800 discloses a swimming pool cleaning device as shown in FIG. 1. The cleaning device has an outer shell (2). The outer shell has a roller (20) and wheel (11) at its bottom (2a). Roller (20) and wheel (11) are driven by a motor placed inside the outer shell (2). By means of the roller (20) mechanical action, could effectively pick up dirt and debris settled at the swimming floor through the intake port (5) located on the bottom (2a) of the outer shell (20). The roller (20) generally consists of a rigid roller body and a flexible roller brush wrapped around the roller body.
The roller used in existing swimming pool cleaning devices as shown by example in FIG. 2 includes a rigid roller body (21) and a flexible roller brush (21) wrapped around the rigid roller body (21). The rigid roller body (21) axle is connected to a motor placed inside the swimming pool cleaning device and driven by this motor. The roller brush (22) has an inner surface in contact with the roller body (21) outer surface. The roller brush (22) outer surface has a number of flexible brushes sticking out. Such brushes are used to increase friction and stir up the dirt and debris, which has settled on the swimming pool floor.
To handle the above mentioned existing problems, known cleaning devices have been designed to raise the floor clearance as illustrated in FIG. 3. By adding a skirt (300) at the intake port, dirt and debris is stirred as the swimming pool cleaning device moves. Typically, the skirt (300) is made from elastic material or makes a hinge such as an elastic axle between the skirt (300) and intake port to enable the skirt (300) to swing when it meets dirt segregated and stirs it up without affecting swimming pool cleaning device motion. The skirt has been proven to lower the effective floor clearance of the pool cleaning vehicle at the intake port. However, if the skirt (300) is effectively lowered too far, it will only push the dirt around instead of pulling it into the cleaning device. Normally, the roller brush (22) is a plastic sheet having a length equals to the circumference of the roller body (21). The roller body (21) circumference is wrapped by the roller brush (22), fixed by a number of connectors (24) along both ends of the roller brush (22), forms a roller (20). The roller brush (22) and the roller body (21) are initially tightly engaged. However, as sunlight and swimming pool chemicals make the roller brush (22) more relaxed, it will get looser and the gap between the roller body (21) and roller brush (22) will increase and the engagement will have a tendency to slip.
In order to avoid slippage, applicant herein discloses a design using a shorter roller brush (22) so that roller body (21) remains tightly wrapped by the roller brush (22), reducing the likelihood that the gap between roller brush (22) and roller body (21) will grow. By changing the design of prior brushes, Applicants herein seek to increase the roller brush life and make construction more efficient.